Drug delivery systems using nanoparticle-based therapeutic and diagnostic agents have been developed for the treatment and diagnosis of various diseases including cancers. One of the properties commonly given to nanoparticles applied to the drug delivery system is stealth property (immune response evasion capacity in the blood, that is, retention in the blood). The means for imparting stealth property to nanoparticles is a surface modification. For example, it is known to coat nanoparticles with various polymers such as polyethylene glycol for exerting an effect of preventing opsonin adsorption or aggregation. It is also known to coat nanoparticles with a self-marker CD47 protein for the purpose of inhibiting phagocytosis (Non-Patent Document 1 and Non-Patent Document 2).
Meanwhile, a molecular imprinting method (MI method) is known as an artificial receptor synthesis method capable of specifically recognizing a target molecule. The MI method is a method of artificially constructing a binding site having selectivity for a target molecule in a material with use of a recognition object molecule (a target molecule) as a template. The polymer synthesized using the MI method is called a molecularly imprinted polymer (MIP). The MIP is constructed by radical polymerization of a template molecule (a target molecule or a derivative thereof) and a functional monomer (a molecule having a site interacting specifically with a template molecule and a polymerizable functional group) together with a crosslinking agent, followed by removal of the template molecule from within the polymer (Non-Patent Document 3).